The present invention relates to a reproduction signal evaluation method of evaluating the quality of a reproduction signal reproduced from an information recording medium on which digital information is recorded. The present invention also relates to an information recording medium on which digital information is recorded. In addition, the present invention relates to an information reproduction apparatus for reproducing digital information from an information recording medium on which digital information is recorded.
Recent years have seen a remarkable increase in the recording density of information recording media such as optical disks and magnetic disks. With this increase in recording density, the quality margin of reproduction signals read out from media by a digital recording/reproduction apparatus is reduced. For this reason, the state of each record mark on a medium must be accurately specified. In the case of exchangeable media, in particular, consideration must be given in advance to the facts that a single medium is used in a plurality of apparatuses, and a plurality of media are used in a single apparatus. Compatibility must be ensured between the media. That is, the characteristics of a reproduction signal obtained when a medium is played in a predetermined apparatus must be specified. In other words, reproduction signals must be accurately evaluated; otherwise, specifications for compatibility cannot be provided for media.
The present invention has been made in consideration of the above situation and, has as its object to provide the following reproduction signal evaluation method, information recording medium, and information reproduction apparatus:
(1) a reproduction signal evaluation method capable of accurately evaluating reproduction signals obtained by an information recording medium on which predetermined information is recorded at a high density;
(2) an information recording medium on which predetermined information is recorded at a high density under a predetermined condition such that reproduction signals satisfying a predetermined evaluation condition can be obtained; and
(3) an information reproduction apparatus for reproducing information from an information recording medium on which predetermined information is recorded at a high density under a predetermined condition such that reproduction signals satisfying a predetermined evaluation condition can be obtained.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.